Compressor With Muffler

ABSTRACT

A compressor assembly may include a shell, a discharge fitting, a muffler, a compression mechanism, and a motor. The shell may have an opening therethrough with the discharge fitting generally extending therefrom. The muffler may be in communication with the discharge fitting and may be external to the shell. The muffler may have an inlet proximate the discharge fitting, an outlet distal from the discharge fitting, and a body portion extending therebetween. The muffler may include a valve assembly proximate the outlet. The compression mechanism may be contained within the shell and include a suction inlet and a discharge passageway. The discharge passageway may be connected to the opening in the shell for direct discharge of refrigerant from the compression mechanism to the discharge fitting. The motor may be contained within the shell and drivingly coupled to the compression mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/984,908, filed on Nov. 2, 2007. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to scroll compressors, and morespecifically to scroll compressor having mufflers.

BACKGROUND AND SUMMARY

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Direct discharge refrigerant compressors for cooling systems such as airconditioning, refrigeration or chiller systems, may include an externalmuffler to reduce a discharge pressure pulse and/or noise. Thesecompressors may also include a device to prevent backflow duringshutdown in order to prevent motor damage. When the compressor is shutdown, the compression mechanism is at a lower pressure than thedischarge fitting and the external muffler. Without backflow prevention,refrigerant reverses direction in the high-pressure region of thedischarge fitting and flows into the compression mechanism. Thisbackflow may cause the compression mechanism to operate in reverse,resulting in noise and potential motor damage.

A compressor assembly includes a shell, a discharge fitting, a muffler,a compression mechanism, and a motor. The shell includes an openingtherethrough with the discharge fitting generally extending therefrom.The muffler is in communication with the discharge fitting and may beexternal to the shell. The muffler includes an inlet proximate thedischarge fitting, an outlet distal from the discharge fitting, and abody portion extending therebetween. The muffler may include a valveassembly proximate the outlet. The compression mechanism may becontained within the shell and include a suction inlet and a dischargepassageway. The discharge passageway may be connected to the opening inthe shell for direct discharge of refrigerant from the compressionmechanism to the discharge fitting. The motor may be contained withinthe shell and drivingly coupled to the compression mechanism.

The first valve assembly may be located within the body portion of themuffler.

In a variation, the first valve assembly may be contained within theoutlet of the muffler. The outlet includes a first portion internal tothe body portion and a second portion external to the body portion. Thefirst valve assembly may be located within the second portion of theoutlet. In an alternate arrangement, the first valve assembly may belocated within the first portion of the outlet. The outlet may include atubular member secured to the muffler body portion, a valve seat securedto the tubular member, and a valve stop. The valve seat and the valvestop define a valve chamber. The valve assembly may include a valvemember disposed within the valve chamber and movable between a closedposition where the valve member abuts the valve seat and an openposition where the valve member abuts the valve stop.

The compressor may additionally include a second valve assembly disposedbetween the discharge passageway and the first valve assembly. The firstvalve assembly may be configured to move to a closed position when adirection of flow is from the outlet to the inlet. The closed positionmay generally prevent flow from passing from the outlet to the inlet.The first valve assembly may be configured to move to an open positionwhen a direction of flow is from the inlet to the outlet. The openposition may generally allow flow to pass from the inlet to the outlet.

The compression mechanism may include first and second scroll membersmeshingly engaged with one another to form a plurality of intermediatecompression pockets and a discharge pocket. A first and second of theintermediate pockets immediately adjacent to the discharge pocket definea compression volume immediately prior to communication between thefirst and second intermediate pockets and the discharge pocket. A ratiobetween a total volume of the muffler and the compression volume may bebetween 5-to-1 and 20-to-1. A ratio between a cross-sectional area ofthe muffler taken generally perpendicular to a fluid flow directiontherethrough and a cross-sectional area of the inlet may be greater than20-to-1.

Further, the first valve assembly may be biased to an open position bygravity.

In another arrangement, a compressor assembly may include a compressorhaving a discharge fitting extending therefrom and a muffler assembly.The muffler assembly may include a muffler having an inlet, an outlet,and a body portion disposed between the inlet and the outlet. The inletis in communication with the discharge fitting. At least a portion ofthe inlet may be external to the compressor and the outlet may have avalve assembly contained therein.

The outlet includes a first portion internal to the body portion and asecond portion external to the body portion. The valve assembly may belocated within the second portion of the outlet. Alternatively, thevalve assembly may be located within the first portion of the outlet.The outlet may include a tubular member secured to the muffler bodyportion, a valve seat secured to the tubular member, and a valve stop.The valve seat and the valve stop define a valve chamber. The valveassembly includes a valve member disposed within the valve chamber andmoveable between a closed position where the valve member abuts thevalve seat and an open position where the valve member abuts the valvestop.

Further, the valve assembly may be biased to an open position bygravity.

A direct discharge compressor muffler may include an inlet, an outlet, abody portion disposed between the inlet and outlet, and a valveassembly. The valve assembly may be contained within the muffler andproximate the outlet. The valve assembly is configured to prevent flowfrom passing in a direction from the inlet to the outlet.

The valve assembly may be contained within the outlet. The outletincludes a first portion internal to the body portion and a secondportion external to the body portion. The valve assembly may be locatedwithin the second portion of the outlet. Alternatively, the valveassembly may be located within the first portion of the outlet. Theoutlet may include a tubular member secured to the muffler body portion,a valve seat secured to the tubular member, and a valve stop. The valveseat and the valve stop define a valve chamber. The valve assemblyincludes a valve member disposed within the valve chamber and moveablebetween a closed position where the valve member abuts the valve seatand an open position where the valve member abuts the valve stop.

The valve assembly may be located within the body portion. The valveassembly may be biased to an open position by gravity.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present claims.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the teachings in any way.

FIG. 1 is a section view of a compressor and muffler assembly;

FIG. 2 is a section view of the compressor of FIG. 1;

FIG. 3 is a section view of a muffler assembly;

FIG. 4 is a section view of an alternate muffler assembly;

FIG. 5 is a section view of a compressor; and

FIG. 6 is a schematic illustration of wraps of the compressor of FIG. 1.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present teachings, application, or uses.

The present teachings are suitable for incorporation in many differenttypes of scroll and rotary compressors, including hermetic machines,open drive machines and non-hermetic machines. For exemplary purposes, acompressor assembly 10 is shown including a hermetic scroll refrigerantmotor-compressor 12 of the low-side type, i.e., where the motor andcompressor are cooled by suction gas in the hermetic shell, asillustrated in the vertical section shown in FIGS. 1, 2, 4 and 5.

As shown in FIGS. 1 and 2, compressor assembly 10 includes compressor 12and an external muffler assembly 14. Compressor 12 may include acylindrical hermetic shell 16, a compression mechanism 18, a mainbearing housing 20, a motor assembly 22, a refrigerant discharge fitting24, and a suction gas inlet fitting 26. The hermetic shell 16 may housethe compression mechanism 18, main bearing housing 20, and motorassembly 22. Shell 16 may include an end cap 28 at the upper endthereof. The refrigerant discharge fitting 24 is attached to shell 16 atopening 30 in end cap 28. The suction gas inlet fitting 26 is attachedto shell 16 at opening 32. The compression mechanism 18 is driven bymotor assembly 22 and supported by main bearing housing 20. The mainbearing housing 20 may be affixed to shell 16 at a plurality of pointsin any desirable manner.

The motor assembly 22 generally includes a motor 34, a frame 36 and acrankshaft 38. The motor 34 includes a motor stator 40 and a rotor 42.The motor stator 40 may be press fit into frame 36, which may in turn bepress fit into shell 16. Crankshaft 38 is rotatably driven by stator 40.Windings 44 pass through stator 40. Rotor 42 may be press fit oncrankshaft 38. A motor protector 46 may be provided in close proximityto windings 44 so that motor protector 46 will de-energize motor 34 ifwindings 44 exceed their normal temperature range.

Crankshaft 38 may include an eccentric crank pin 48 and one or morecounter-weights 50 at an upper end 52. Crankshaft 38 may be rotatablyjournaled in a first bearing 54 in main bearing housing 20 and in asecond bearing 56 in frame 36. Crankshaft 38 may include an oil-pumpingconcentric bore 58 at a lower end 60. Concentric bore 58 may communicatewith a radially outwardly inclined and relatively smaller diameter bore62 extending to the upper end 52 of crankshaft 38. The lower interiorportion of shell 16 is filled with lubricating oil. Concentric bore 58may provide pump action in conjunction with bore 62 to distributelubricating fluid to various portions of compressor 12.

Compression mechanism 18 may generally include an orbiting scroll 64 anda non-orbiting scroll 66. Orbiting scroll 64 may include an end plate 68having a spiral vane or wrap 70 on the upper surface thereof and anannular flat thrust surface 72 on the lower surface. Thrust surface 72may interface with an annular flat thrust bearing surface 74 on an uppersurface of main bearing housing 20. A cylindrical hub 76 may projectdownwardly from thrust surface 72 and may include a journal bearing 78having a drive bushing 80 rotatively disposed therein. Drive bushing 80may include an inner bore in which crank pin 48 is drivingly disposed.Crank pin 48 may have a flat on one surface (not shown) that drivinglyengages a flat surface in a portion of the inner bore of drive bushing80 to provide a radially compliant driving arrangement, such as shown inassignee's U.S. Pat. No. 4,877,382, the disclosure of which is hereinincorporated by reference.

Non-orbiting scroll member 66 may include an end plate 82 having anon-orbiting spiral wrap 84 on lower surface 86 thereof. Non-orbitingspiral wrap 84 may form a meshing engagement with wrap 70 of orbitingscroll member 64, thereby creating an inlet pocket 88, intermediatepockets 90, 92, 94, 96, and discharge pocket 98. Non-orbiting scroll 66may have a centrally disposed discharge passageway 100 in communicationwith discharge pocket 98 and upwardly open recess 102 which may be influid communication with discharge fitting 24. A floating seal 104 maybe located around recess 102 and may abut shell 16, thereby providingsealed communication between discharge passageway 100 and dischargefitting 24, while allowing axial displacement of non-orbiting scroll 66relative to shell 16.

Non-orbiting scroll 66 may be mounted to main bearing housing 20 in anymanner that will provide limited axial movement of non-orbiting scrollmember 66. For a more detailed description of the non-orbiting scrollsuspension system, see assignee's U.S. Pat. No. 5,055,010, thedisclosure of which is hereby incorporated herein by reference. Axialpressure biasing may be included in compressor 12, as disclosed inassignee's aforesaid U.S. Pat. No. 4,877,382, A capacity modulationsystem may also be included in the system, as described in assignee'saforesaid U.S. Pat. No. 6,821,092.

Relative rotation of the scroll members 64, 66 may be prevented by anOldham coupling, which may generally include a ring 108 having a firstpair of keys 110 (one of which is shown) slidably disposed indiametrically opposed slots 112 (one of which is shown) in non-orbitingscroll 66 and a second pair of keys (not shown) slidably disposed indiametrically opposed slots in orbiting scroll 64.

External muffler assembly 14 may include an inlet 114, an outlet 116,and a body portion 118 extending therebetween. A first end 120 of inlet114 may extend into an inlet opening 122 in body portion 118. A secondend 124 of inlet 114 may extend into and be coupled to refrigerantdischarge fitting 24.

Outlet 116 may include first and second portions 126, 128 with aconnecting portion 130 disposed therebetween. First and second portions126, 128 may be generally tubular with second portion 128 having adiameter greater than the diameter of first portion 126. Connectingportion 130 may have a radial extent and generally form a stoppingmember.

A valve seat 132 may be located at an inlet to second portion 128. Valveseat 132 may include apertures 134, 136 for passage of a flowtherethrough. Second portion 128, connecting portion 130, and valve seat132 may define a valve chamber 138. Valve chamber 138 may house a valvemember 140 therein.

Valve member 140 may include a disk-shaped body portion 142 having acentrally-disposed aperture 144 therethrough. Valve member 140 may bedisplaceable from a closed position to an open position by a flow movingin a direction from second portion 128 to first portion 126 and from anopen position to a closed position by a flow moving from first portion126 to second portion 128. When in a closed position, body portion 142may generally cover apertures 134, 136. When in an open position, valvemember 140 may be forced away from apertures 134, 136 and generallytoward connecting portion 130.

In the example shown in FIG. 1, body portion 118 is shown including anoutlet opening 146 having a diameter generally equal to the diameter offirst portion 126 of outlet 116. As such, first portion 126 may extendthrough outlet opening 146 while second portion 128 and connectingportion 130 may be located within body portion 118.

In FIG. 3, an external muffler assembly 214 is shown generally similarto external muffler assembly 14, with the exception of outlet opening246 and outlet 216. Specifically, outlet 216 is generally locatedexternal to body portion 218, as described below. Outlet opening 246 mayhave a diameter generally similar to the diameter of second portion 228.As such, second portion 228 is disposed outside of body portion 218.More specifically, valve seat 232 is located in outlet opening 246,resulting in valve chamber 238 and valve member 240 being locatedoutside of body portion 218.

In yet another example, shown in FIG. 4, an external muffler assembly314 is shown generally similar to external muffler assembly 214.However, external muffler assembly 314 is rotated approximately onehundred and eighty degrees relative to external muffler assembly 214using U-shaped inlet conduit 414. Rather than being biased to a closedposition by gravity as seen in FIG. 3, valve member 340 may be biased toan open position by gravity. Valve member 340 may be forced to a closedposition during reverse-flow conditions.

While described in FIGS. 1-4 as having valve member 140, 240, 340located within outlet 116, 216, valve member 140, 240, 340 mayadditionally or alternatively be located within body portion 118, 218,generally before second portion 128, 228 of outlet 116, 216. In anotherarrangement, shown in FIG. 5, a second valve member 248 may be locatedbetween external muffler assembly 14, 214 and non-orbiting scroll 66.More specifically, second valve member 248 may be located within recess102 above discharge passageway 100. Second valve member 248 is shownhaving plate-like structure 250 and a hinge connection 252. However, anysuitable valve assembly may be used, such as one similar to valve member140. Also, any combination of FIGS. 1-5 may be used.

With reference to FIGS. 1, 3, 4 and 6, the ratio between the volume ofmuffler assembly 14, 214, 314 more specifically body portion 118, 218,and the intermediate pockets 92, 97 immediately adjacent to dischargepocket 98 before communication between intermediate pockets 92, 97 anddischarge pocket 98 may be between 5-to-1 and 20-to-1. Intermediatepockets 92 and 97 may be combined with discharge pocket 98 during aportion of the orbit of orbiting scroll 64 (seen in FIGS. 1, 2 and 5). Aratio between the cross-sectional area of body portion 118, 218 takengenerally perpendicular to a flow direction (D) and the cross-sectionalarea of inlet 114 may generally be greater than or equal to 20-to-1.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

1. A compressor assembly comprising: a shell having an openingtherethrough; a discharge fitting generally extending from said openingin said shell; a muffler in communication with said discharge fittingand external to said shell, said muffler having an inlet proximate saiddischarge fitting, an outlet distal from said discharge fitting, and abody portion extending therebetween; a first valve assembly disposedproximate said outlet of said muffler; and a compression mechanismdisposed within said shell and including a discharge passageway incommunication with said opening in said shell for direct discharge ofrefrigerant from said compression mechanism to said discharge fitting.2. The compressor assembly of claim 1, wherein said first valve assemblyis located within said body portion.
 3. The compressor assembly of claim1, wherein said first valve assembly is contained within said outlet,said outlet having a first portion internal to said body portion and asecond portion external to said body portion.
 4. The compressor assemblyof claim 3, wherein said first valve assembly is located within saidsecond portion of said outlet.
 5. The compressor assembly of claim 3,wherein said first valve assembly is located within said first portionof said outlet.
 6. The compressor assembly of claim 3, wherein saidoutlet includes a tubular member secured to said muffler body portion, avalve seat secured to said tubular member, and a valve stop, said valveseat and said valve stop defining a valve chamber, said valve assemblyincluding a valve member disposed within said valve chamber and movablebetween a closed position where said valve member abuts said valve seatand an open position where said valve member abuts said valve stop. 7.The compressor assembly of claim 1, further comprising a second valveassembly disposed between said discharge passageway and said first valveassembly.
 8. The compressor assembly of claim 1, wherein said firstvalve assembly is configured to move to a closed position when adirection of flow is from said outlet to said inlet, said closedposition generally preventing flow from passing from said outlet to saidinlet.
 9. The compressor assembly of claim 1, wherein said first valveassembly is configured to move to an open position when a direction offlow is from said inlet to said outlet, said open position generallyallowing flow to pass from said inlet to said outlet.
 10. The compressorassembly of claim 1, wherein said compression mechanism includes firstand second scroll members meshingly engaged with one another to form aplurality of intermediate compression pockets and a discharge pocket, afirst and second of said intermediate pockets immediately adjacent tosaid discharge pocket defining a compression volume immediately prior tocommunication between said first and second intermediate pockets andsaid discharge pocket, a ratio between a total volume of said mufflerand said compression volume being between 5-to-1 and 20-to-1.
 11. Thecompressor assembly of claim 1, wherein a ratio between across-sectional area of said muffler taken generally perpendicular to afluid flow direction therethrough and a cross-sectional area of saidinlet being greater than 20-to-1.
 12. The compressor assembly of claim1, wherein said first valve assembly is biased to an open position bygravity.
 13. A compressor assembly comprising: a compressor having adischarge fitting extending therefrom; and a muffler assembly includinga muffler having an inlet, an outlet, and a body portion disposedbetween said inlet and said outlet, said inlet in communication withsaid discharge fitting, at least a portion of said inlet being externalto said compressor, said outlet having a valve assembly containedtherein.
 14. The compressor assembly of claim 13, wherein said outletincludes a first portion internal to said body portion and a secondportion external to said body portion.
 15. The compressor assembly ofclaim 14, wherein said valve assembly is located within said secondportion of said outlet.
 16. The compressor assembly of claim 14, whereinsaid valve assembly is located within said first portion of said outlet.17. The compressor assembly of claim 14, wherein said outlet includes atubular member secured to said muffler body portion, a valve seatsecured to said tubular member, and a valve stop, said valve seat andsaid valve stop defining a valve chamber, said valve assembly includinga valve member disposed within said valve chamber and movable between aclosed position where said valve member abuts said valve seat and anopen position where said valve member abuts said valve stop.
 18. Thecompressor assembly of claim 14, wherein said valve assembly is biasedto an open position by gravity.
 19. A direct discharge compressormuffler comprising: an inlet; an outlet; a body portion disposed betweensaid inlet and said outlet; and a valve assembly contained within saidmuffler proximate said outlet, said valve assembly configured to preventflow from passing in a direction from said inlet to said outlet.
 20. Themuffler of claim 19, wherein said valve assembly is contained withinsaid outlet.
 21. The muffler of claim 20, wherein said outlet includes afirst portion internal to said body portion and a second portionexternal to said body portion.
 22. The muffler of claim 21, wherein saidvalve assembly is located within said second portion of said outlet. 23.The muffler of claim 21, wherein said valve assembly is located withinsaid first portion of said outlet.
 24. The muffler of claim 20, whereinsaid outlet includes a tubular member secured to said muffler bodyportion, a valve seat secured to said tubular member, and a valve stop,said valve seat and said valve stop defining a valve chamber, said valveassembly including a valve member disposed within said valve chamber andmovable between a closed position where said valve member abuts saidvalve seat and an open position where said valve member abuts said valvestop.
 25. The muffler of claim 19, wherein said valve assembly islocated within said body portion.
 26. The muffler of claim 19, whereinsaid valve assembly is biased to an open position by gravity.